Mitigation of Biomolecular Adsorption with Hydrophilic Polymer Additives

• US 20090280251A1
• Filed: 05/18/2006
• Published: 11/12/2009
• Est. Priority Date: 05/21/2005
• Status: Active Grant

• Current Assignee: Advanced Liquid Logic, Inc. (Illumina Incorporated)
• Original Assignee: Core-Microsolutions Incorporated
• Inventors: Liu, Wayne Po-Wen, De Guzman, Peter-Patrick, Yi, Brandon Uichong
• Granted Patent: US 8,481,125 B2
• Time in Patent Office: Days
• US Class Current: 427/299
• CPC Class Codes: B01J 2219/00837 comprising coatings other than catalytically active coatings
• CPC Class Codes: B01L 2200/12 Specific details about manufacturing devices
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2300/165 Specific details about hydrophobic, oleophobic surfaces
• CPC Class Codes: B01L 2400/0418 electro-osmotic flow [EOF]
• CPC Class Codes: B01L 2400/0421 electrophoretic flow
• CPC Class Codes: B01L 2400/0424 Dielectrophoretic forces
• CPC Class Codes: B01L 2400/0427 Electrowetting
• CPC Class Codes: B01L 3/502792 for moving individual droplets on a plate, e.g. by locally altering surface tension
• CPC Class Codes: Y10T 428/139 Open-ended, self-supporting conduit, cylinder, or tube-type article

Abstract

Molecular adsorption to the microfluidic device surfaces can be passively and actively mitigated by mixing certain hydrophilic polymers (organic polymers with repeating hydrophilic groups—the preferred polymers being amphipathic surfactants—with the sample liquid during or prior to relevant microfluidic operations. Nonionic surfactants such as polyoxyethylene sorbitan monooleate and polyoxyethylene octyl phenyl ether are especially effective. High molecular weight polyethylene polymers are also effective. The hydrophilic polymers appear to prevent binding of the fouling molecules to the microfluidic by occupying the surface sites in place of the fouling molecules or by interacting with the fouling molecules to prevent binding of the fouling molecules the surface. When surface adsorption is thus mitigated, microfluidic devices can readily handle samples containing biomolecules to enable active sample concentration, filtering, washing, transport, mixing and other sample handling operations.

Claims

1. A method for preventing adsorption of molecules to surfaces in microfluidic devices comprising the step of adding a quantity of hydrophilic polymer effective to prevent surface adsorption of samples used in the microfluidic devices.

2. The method according to claim 1, wherein the hydrophilic polymer is a nonionic surfactant.

3. The method according to claim 2, wherein the nonionic surfactant is selected from the group consisting of polyoxyethylene octyl phenyl ether and polyoxyethylene sorbitan monooleate.

4. The method according to claim 2, wherein the nonionic surfactant is selected from the group consisting of polyethylene glycol and methoxypolyethylene glycol.

5. The method according to claim 1, wherein the microfluidic device employs effects selected from the group consisting of mechanical, electrical, optical, chemical and combinations thereof.

6. The method according to claim 5, wherein the microfluidic device employs droplets.

7. The method according to claim 5, wherein electrical effects are used to implement mechanisms selected from the group consisting of electrowetting, opto-electrowetting, electrostatic, electrophoretic, dielectrophoretic, electro-osmotic and combinations thereof.

8. The method according to claim 7, wherein electrical effects are used to manipulate droplets.

9. The method according to claim 7, wherein the microfluidic device employs an electrowetting mechanism.

10. A method for selecting an optimal hydrophilic polymer for prevention of fouling an electrowetting microfluidic device comprising the steps of:

processing a first aliquot of a fluid sample containing a potential fouling agent using an electrowetting microfluidic device; and

testing a panel of candidate hydrophilic polymers if the electrowetting microfluidic device was fouled by the first aliquot by;

adding increasing amounts of each member of the panel of candidate hydrophilic polymers to a plurality of aliquots of the fluid sample so that there are aliquots containing a range of concentrations of each member;

processing each of the aliquots of the plurality to determine whether any of the aliquots prevents fouling; and

selecting the optimal hydrophilic polymer as the member of the panel which prevents fouling at the lowest concentration.

11. The method according to claim 10, wherein the hydrophilic polymers are surfactants.